Yarn tensioning device



13, E. c'. GWALTNEY E'F AL 2,405,885

YARN TENSIONING DEVICE Filed Feb. 15, 1945 Patented Aug. 13, 19462,405,885 YARN TENSIONING DEVICE Eugene C. Gwaltney, Biddeford, andHenry R. Marsh, Saco, Maine, assignors to Saco-Lowell Shops, Boston,Mass., at corporation-of Maine Application February 15, 1945, Serial'No. 578,031 I 8 Claims.

This invention relates to devices for applying a tension or drag to atravelling yarn or thread. Such devices are commonly used in aconsiderable variety of textile machinery and the present invention isdirected more especially to the requirements of those articles of thischaracter in which an exceptionally uniform degree of tension must bemaintained, and in which also a very accurate adjustment of the degreeof tension is necessary.

For example, these requirements are extremely important in twistingmachines of the so-oalled 2 for 1 type. In them the yarn is drawn from asupply body, usually stationary, and customarily is guided through thatbody along its axis to a flier revolving around said axis. From the eyeof the flier the yarn is fed to a stationary guide eye, usually locatedabove and in line with said body, and then passes to a wind-upmechanism. When the flier is run at high speeds the balloon formedbetween the flier and the stationary guide eye tends to become excessiveand a, very accurate control of the tension between the supply body andthe flier is essential in controlling the size of the balloon.

The present invention aims to devise a tension device which will satisfythese requirements, which can be manufactured economically, will beexceptionally reliable in operation, and which can be quickly removedfrom the machine and taken apart when necessary for any purpose as, forexample, to remove accumulations of lint and fly.

The nature of the invention will be readily understood from thefollowing description when read in connection with the accompanyingdrawing, and the novel features will be particularly pointed out in theappended claims.

In the drawing,

' Fig. 1 is a side elevation of a tension device embodying thisinvention;

Fig. 2 is a front elevation of the device shown in Fig. 1;

Fig. 3 is a vertical, axial, sectional view of said device, with some ofthe parts shown in elevation; and

Figs. 4 and 5 are transverse, sectional views, considerably enlarged,taken on the lines 6-4 and 5-5, respectively, of Fig. 3.

The construction shown in the drawing comprises a tubular body,indicated in general at 2, provided at one side with a recess and havingtubular yarn guiding sections, indicated at a and b, respectively, aboveand below said'recess In 2 t are mounted, the lower plate'having anapproximately fiat body portion with down-turned or flanged ends 3'3',resting on horizontal shoulders'55 atthe opposite ends of the recess.The other plate 4 is similar to it but is provided with up-turned sidesextending longitudinally of it and also with flanged ends 6 and I. Theseplates have smooth fiat meeting surfaces.

Pressure is applied to the plates by a spring 8 of the leaf type andwhich preferably consists simply of a length of spring wire, suitablybent, as will be described. It is held in place by providing it-with aninturned tip 0, Fig. 3,

at its upper end, which extends into a hole provided in the shank ortubular extension at of the body 2, and it is clamped there by a setscrew iii threadedthrough the base of a cap l2 mounted on the upper endof said shank. This shank also is flattened on one side, as shown at ain Figs. 2 and 4, and the flattened surface is grooved longitudinally toreceive said spring. Below the shank the spring passes through a radialslot i3, Figs. 8 and 4, formed in a flanged section 2 of the body 2, andthen through slots in the two end flanges 6 and l of the upper plate -l.Between these points the spring is provided with an inwardly bentportion or knee (1 which bears on the upper tension plate 4, and at itslower end it has a reversely curved section e, Fig. 3, which rides in aslot 1 formed partly in the lower extension I) of the body 2 and partlyin a yarn guiding bushing H3 secured in said ex tension by a set screw li.

The particular tension device here shown is intended to fit into theupper end of the tubular section 8 of the yarn carrier shown in pendingapplication Ser. No. 495,832, filed July 23, 1943, (now issued as PatentNo. 2,374,085) and to take the place of the tension device illustratedin that application. As the yarn is drawn from the supply bodysurrounding said tubular section, it enters the eye g, Fig. 3, of thecap l2, and travels down through the tubular shank a,

through the bore of the yarn guiding bushing H3 at the lower end of saidshank, passes between the tension plates 3 and l, and out through thesmall bore of the lower yarn guiding bushing M. It will be observed thatthese bushings l4 and l 55 are in axial alignment with each other andwith the yarn tube a and the eye 9. Also, that this axis is in line withthe flat meeting surfaces of the two tension plates 3 and l. Above thetubular guiding section of the shank a, this member is enlarged somewhatto receive a body of said recess lower and upper tension plates 3 andfelt 2d, or

other fibrous material, which bears lightly on the yarn but with enoughpressure to apply a resistance sufficient to straighten out any loops orkinks that may be in it. Consequently, the yarn travels freely throughthe entire body of the tension device except for the very light dragapplied to its at 20 and the main resistance to its movement applied bythe two tension plates. The part 26 is really a pre-tension elementwhich ensures the straightening of the yarn before it passes between thetension plates 3 and 4.

In order to adjust this tension with a high degree of accuracy, anannular slide or ringlB encircles the shank a and carries a set screw l1which may be tightened up to clamp the spring firmly to the shank. Atthe side of the ring opposite the set screw a pin I 8 passes radiallythrough it and is fixed in it, the inner projecting end of this pin, asshown in Fig. 3, riding in a groove formed longitudinally in the shankface a where it prevents any rotative movement of the slide on theshank. Thus the screw l! is always held directly over the spring 8 inall positions of adjustment of the slide lengthwise of the spring.

Both tension plates are held in place by the spring 3. The upper one maybe slipped out of it operative position merely by pressing down- Wardlyon one of its lateral flanges, thus causing it to rotate around thespring 8 and to tip out of place. If, then, the lower plate is lifted atone corner, it will also tip around the knee d and swing to one side ofthe recess where it may be lifted out. Both plates may be returned totheir operative positions by a reversal of the operations justdescribed. I

From the foregoing it will be evident that the active length of thespring 8 utilized in applying pressure to the tension platelil is thatbetween the knee d and the set screw ll. 'Also, that this length can beadjusted accurately by the arrangement above described, and that thegradation of pressure can be made very gradual. These are highlydesirable results, particularly when the device is used in a twister ofthe 2 for 1 type. While the slide alone is effective up to a certaindegree to adjust the active length of the spring, there is a tendency,when the slide alone is used, for the spring to bow outwardly above theslide, and this action reduces the accuracy of the adjustment. However,when the set screw H i tightened up, it clamps the spring securely tothe body, thus increasing very substantially the clamping pressureexerted by the slide itself. This arrangement has been found highlyeffective.

Preferably the intermediate section 2 of the tension body is grooved toreceive a soft rubber bushing 2i, somewhat larger in outside diameterthan the other parts of said body, so that it engages the inner surface'of the central tubular member 8 of the carrier shown in the patent abovereferred to and provides a yielding contact with the bore of saidmember. This bushing has been omitted from Figs. 4 and 5.

Preferably, also, the upper adjacent surfaces of the plates are slightlybevelled or grooved to form a short funnel section, as indicated at h inFig. 5, to assist in guiding the wire customarily used in threading upthe tension device.

The capl2 may be made of any convenient material such, for example, asone of the molded plastics, and it is releasably secured on the body 2by the set screw I ll.

From the foregoing it will be evident that the invention provides a verysimple and compact, but rugged and substantial, form of tension de- 4vice in which those factors controlling the degree of tension applied tothe yarn are capable of very accurate adjustment.

At the same time the tension plates can be quickly removed for cleaningand replaced. The same also is true of the cap 12 and the pre-tensiondevice 20 mounted in it.

While we have herein shown and described a preferred emodiment of ourinvention, it will be evident that the invention may be embodied inother forms without departing from the spirit or scope thereof.

Having thus described our invention, what we desire to claim as new is:

1. A yarn tension device comprising a supporting body through which theyarn is guided, plates supported in said body for pressing the yarnbetween them as it passes through said body, a leaf spring pressing saidplates together, said spring extending in a direction generally parallelto said plates and means for adjusting the pressure so exerted on theyarn comprising a slide bearing against said spring and mounted on saidbody for adjustment lengthwise of the spring.

2. A yarn tension device comprising a supporting body through which theyarn is guided, plates supported in said body for pressing the yarn between them as it passes through said body, a leaf spring pressing saidplates together, means for adjusting the pressure so exerted on the yarncomprising a slide bearing against said spring and mounted on said bodyfor adjustment lengthwise of the spring, and means cooperating with saidspring to increase the pressure applied to the spring by the slideitself.

3. A yarn tension device comprising a supporting body through which theyarn is guided, plates supported in said body for pressing the yarnbetween them as it passes through said body, a leaf spring pressing saidplates together, said spring extending in a direction generally parallelto said plates andmeans for adjusting the pressure so exerted on theyarn comprising a slide bearing against said spring and mounted on saidbody for adjustment lengthwise of the spring, and screw-threaded meanscooperating with said slide to clamp the spring to said body in anyposition of adjustment of said slide.

4. A yarn tension device comprising a supporting body through which theyarn is guided, plates supported in said body for pressin th yarnbetween them as it passes through said body, a leaf spring pressing saidplates together, means for adjusting the pressure so exerted on theyarn, comprising a slide embracing a portion of said body and disposedtransversely thereof but mounted to slide longitudinally of said body,and a device carried by said slide and riding on said spring andadjustable relatively thereto to clamp the spring against said body.

5. A yarn tension device comprising a supporting body through which theyarn is guided, plates supported in said body for pressing the yarnbetween them as it passes through said body, a leaf spring pressing saidplates together, means for adjusting the pressure so exerted on theyarn, comprising a slide embracing a portion of said body and disposedtransversely thereof but mounted to slide longitudinally of said body,and a set screw threaded into a portion of said slide and positioned tobear on said spring, said screw being adjustable to clamp the springagainst said body.

6. A yarn tension device comprising a supporting body provided witha'lateralopen-sided recess and with a tubular yarn guiding shank, twoopposed plates mounted in said recess to grip the yarn between them asit travels through said body, a leaf spring having a portion extendingalong said shank and another portion bearing on one of said plates topress them together, and a slide mounted on said shank to engage saidspring and adjustable to vary the length of said spring efiective toapply pressure to said yarn.

'7. A yarn tension device according to preceding claim 6, in which saidslide carries a set screw to bear on said spring, and means cooperatingwith said slide to guide it during its adjusting movement to maintainsaid set screw in position to bear on said spring at any point in itsrange of adjustment.

8. A yarn tension device comprising a supporting body provided with alateral open-sided recess and with a tubular yarn guiding shank, twoopposed plates mounted in said recess to grip the yarn between them asit travels through said body, said plates having fiat, smooth-meetingsurfaces and oppositely directed flanges, a leaf spring mounted at oneend on said shank and having a free portion extending along said shankand overlying said plates, said spring having a knee bearing on one ofsaid plates to press it against the other, and a slide encircling aportion of said shank and overlying said spring, whereby the slide isadjustable to vary the length of said spring effective to press saidplates together.

EUGENE C. GWALTNEY. HENRY R. MARSH.

